Idemitsu Kosan Company, Limited

Toshimasa Utaka

Hideki Kamano

Kazushi Tamura

Akira Iijima

Hiromichi Arai

Sei-ichi Yano

Koshi Sekizawa

Koichi Eguchi

The invention addresses a problem of providing a lubricating oil composition for gas engines capable of suppressing viscosity increase while reducing a sulfated ash content and excellent in high-temperature detergency and base number retention. The lubricating oil composition is used for gas engines and contains a base oil (A), at least one ash-free additive (B) selected from an ash-free sulfur-based antioxidant (B1) and a hindered amine compound (B2), and a boronated imide-type dispersant (C), and satisfies the following requirements (X1) to (X3): Requirement (X1): the sulfated ash content is 0.2% by mass or less. Requirement (X2): the content of the ash-free additive (B) is 1.2% by mass or less based on the total amount of the lubricating oil composition, provided that in the case where the ash-free additive (B) contains the hindered amine compound (B2), the content of the hindered amine compound (B2) is less than 1.0% by mass based on the total amount of the lubricating oil composition. Requirement (X3): the content of the boron atom derived from the boronated imide-type dispersant (C) is 200 ppm by mass or more based on the total amount of the lubricating oil composition.

Lubricating oil composition

Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

Lubricating oil composition for engine equipped with supercharging mechanism, method for suppressing low-speed pre-ignition in engine equipped with supercharging mechanism using lubricating oil composition, and method for manufacturing lubricating oil composition

The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150&#xb0; C. (T) is 1.6 to 2.9 mPa&#xb7;s, and a ratio of a kinematic viscosity at 40&#xb0; C. (V) [mm/s] to the HTHS viscosity at 150&#xb0; C. (T) [mPa&#xb7;s] (V/T) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

A lubricating oil composition for an internal combustion engine according to the present invention contains a lubricating base oil, (A1) a basic calcium salicylate having a TBN of 200 mgKOH/g or more, (A2) a basic sodium sulfonate having a TBN of 200 mgKOH/g or more and/or a basic calcium sulfonate having a TBN of 50 mgKOH/g or less, (B) a binuclear organic molybdenum compound and/or a trinuclear organic molybdenum compound, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or less, a total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds being 0.025 mass % or more relative to the whole amount of the composition and the lubricating oil composition having predetermined values of a high-temperature high-shear viscosity and a NOACK value (250&#xb0; C., 1 hr).

Lubricating oil composition for internal combustion engine

A lubricating oil composition of the present invention for an internal combustion engine is prepared by blending (A) a perbasic calcium sulfonate and/or a perbasic calcium phenate having a TBN of 200 mgKOH/g or higher, (B) predetermined binuclear and/or trinuclear organic molybdenum compounds, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or lower into a lubricating base oil composed of a mineral oil and/or a synthetic oil, in which the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher based on the total amount of the composition, and in which the lubricating oil composition has a high-temperature high-shear viscosity at 100&#xb0; C. of 4.0 to 5.0 mPa&#xb7;s, a high-temperature high-shear viscosity at 150&#xb0; C. of 2.5 mPa&#xb7;s or lower and a NOACK value (250&#xb0; C., 1 hr) of 15% by mass or less.

Lubricant composition for internal combustion engine

The invention provides a carbon monoxide conversion method for hydrogen-containing gas. The method comprises selective CO conversion in hydrogen-containing gas through contact of CO with steam and oxygen in the presence of a catalyst containing copper, alumina and zinc oxide.

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Chiba, Japan

Toshimasa Utaka